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A NEW SPECIES OF SHELL-A NEW SPECIES OF SHELL-
FORMING SEA ANEMONE FORMING SEA ANEMONE
FROM AUSTRALIAFROM AUSTRALIA
Andrea L. Crowther
Department of Ecology and Evolutionary Biology
OverviewOverview
• Associations between hermit crabs and
anemones occur in nature
• Hermit crab and Stylobates
• Described species of Stylobates
• New species found from Australia
Hermit crab and anemonesHermit crab and anemones
• Hermit crabs live in
abandoned snail shells
• Anemones attach to shell
• Crabs change shells as
grow, sometimes transfer
anemones
• From shallow tropical
areas to deep sea
• General dynamics of
relationshipshttp://www.divegallery.com/hermit_crab2.htm
StylobatesStylobates
• Deep sea (300-1000 m)
• Always host to hermit crab
• Obligate symbiosis for anemone
• Shell-forming!
• One anemone per crab
Benefits for the symbiontsBenefits for the symbionts
• For the crab
– Protection
– Shell to live in
– Long term
accommodation
• For the anemone– Transport– Food availability
The shellThe shell
• Carcinoecium
• Chitinous secretion
• Anemone coats and
extends hermit crab’s
shell
• Mistaken for a snail’s
shell
http://s190418054.onlinehome.us/portal/2003/0312mon.pdf
Co-evolutionCo-evolution
www.es.ucl.ac.uk/schools/Glossary/gastropod.jpg www.glaucus.org.uk/Hermit4.htm
www.aqualandpetsplus.com.Bug.%20Hermit%20Crabs.htm
??
Stylobates aeneusStylobates aeneus
• Original description of
shell
• Anemone discarded!
• Location: Hawaii and
Guam (Pacific Ocean)
• 402-797 m deep
Stylobates Stylobates distributiondistributionStylobates aeneus; Stylobates cancrisocia; Stylobates loisetteae; Stylobates n.sp.
Stylobates cancrisociaStylobates cancrisocia
• Location: East Africa
(Indian Ocean)
• 818 m deep
• 3 specimens
Stylobates loisetteaeStylobates loisetteae
• Location: west coast
of Australia
• 320-508 m deep
• Wide oral disc
• Oral disc position
A new speciesA new species
• Location: north east
Australia
• 680-960 m deep
• 10 specimens
• Size ranging from
5-9 cm length
• Study of morphology
Species comparisonsSpecies comparisons
S. aeneus S. cancrisocia S. loisetteae New species
Locality Hawaii/Guam E. Africa W. Australia E. Australia
Marginal sphincter muscle
Endodermal, circumscribed,
pinnate
Endodermal, circumscribed,
pinnate
Endodermal, circumscribed,
pinnate
Endodermal, circumscribed,
palmate
Orientation on shell
Mouth behind and below aperture of
shell
Mouth near aperture of
shell
Mouth facing away from aperture of
shell
Mouth near aperture of
shell
ReviewReview
• Stylobates anemones are found in the deep sea
• Form associations with hermit crabs
• Produce carcinoecium
• New species found from north east coast of
Australia
AcknowledgmentsAcknowledgments
• Supervisors:
– Dr. Daphne Fautin (KU)
– Dr. Carden Wallace (MTQ, Australia)
• Collectors:
– Dr. Alistair Birtles (JCU, Australia)
– The late Dr. Peter Arnold (MTQ, Australia)
• Sigma Xi
• Questions?